“Explaining where a belief came from doesn’t show whether it’s true” cuts against the theist too. And debunking isn’t the only naturalist option; tracking accounts hold that selection favored beliefs that track real moral facts.

Both points are fair. The genetic fallacy warning applies symmetrically, so evolution explains moral feelings is not treated here as a refutation of realism; it is a challenge the naturalist realist must answer, which is Sharon Street’s debunking argument turned against naturalism itself. Tracking accounts are the naturalist’s reply to Street. The theist’s response to tracking accounts is that they require independent moral facts for the tracking to track, which reopens the grounding question. That three-step exchange is the state of the debate.